Deficits in making eye contact and limited ability to benefit from communicative and affective information provided through gaze are amongst the defining features of Autism Spectrum Disorders (ASD) in the second and third year. Considering that gaze perception (GP) constitutes one of the key components of social cognition these early deficits are likely to have a cascading effect on the development of more complex social-cognitive skills later on. Identification of specific GP skills that are impaired or spared by the pathogenic factors in ASD will be crucial for isolating the underlying mechanisms, designing diagnostic instruments for infants, as well as selecting specific skill areas for treatment. The specific aims of Project II are to examine whether infants with ASD: (1) have impaired detection of and preference for faces with direct gaze; (2) show selective impairment in detecting gaze-related spatial contingencies; (3) have impairments in perception of gaze-related intentional actions. We will also explore a possibility of identifying subtypes within the autism spectrum with regard to GP skills as well as the relationship between GP abnormalities and cognitive, social, adaptive and communicative functioning. The experimental outcome measures will be derived from visual fixation patterns and saccadic reaction measures recorded using an eye-tracking system. Participants will include 12- to 24-month-old infants with ASD (N=60), Developmental Delays (DD) (N=60), and Typical Developing (TD) controls (N=60). Targeting 12- to 24-month-old infants will allow the examination of the emerging deficits in gaze processing in ASD at the same time as these skills develop and become fully functional in typical development and before their expression can be altered by treatment (e.g., through explicit training to attend to faces and eyes). Through Project II we are striving to discover behavioral markers of ASD in infants, which could subsequently be utilized to develop feasible screening methods for infants. Further, identification of the aspects of gaze processing that are impaired and those that are preserved in ASD will provide valuable indicators regarding the neural mechanisms that might be affected or preserved in late infancy, a period in which functional brain imaging is still very difficult to implement.